It is known in the prior art to provide breather caps (protector caps) on the ends of plastic tubing and barbed connectors during sterilization, in breather bags, of packs containing them. Such caps include a multiplicity of circumferentially spaced passages around the tapered inner surface for cooperation with a tubing or connector end portion to permit sterilant to move over the connector end during bag sterilization; these prior art devices included a reduced diameter end portion, circular in cross-section, inside diameter being reduced gradually through a portion between the tapered portion and the reduced diameter portion.